The Natural History of Dark-Phase Hawks

I wish I had photos to illustrate this post, but I don’t, it’s just something that’s been on my mind.

I’m not sure I’d ever laid eyes on a dark-phase Red-tailed Hawk before I moved to Eastern Oregon. Now I see them all the time. (At first, I’m embarrassed to admit, I think I mistook a few of them for Golden Eagles. Western raptors are still a new thing for me.) Click here for a photo of a typical Red-tailed Hawk, and here for a photo of the dark variety. Same species, two very different-looking birds.

A number of other Buteo raptors also have dark and light morphs – Swainson’s Hawks, Rough-legged Hawks, and Ferruginous Hawks are all found here and all include both dark and light birds. This variation is genetic (think of hair color in humans), and while dark birds are generally less common that light birds in every species, this varies by geography – you’re more likely to see a dark Red-tailed or Ferruginous Hawk out west, more likely to see a dark Rough-legged Hawk back east. What I want to know is, why? Is natural selection at work here, and if so, how are different color morphs adaptive for different regions? Continue reading “The Natural History of Dark-Phase Hawks”

Crowdsourcing Insect ID

One day last week a woman came into the office carrying a cardboard box and asking if there was a biologist around.

Last time something like this happened, the box contained a baby bat, but thankfully this time it was just a mysterious insect nest… thing… on a pine branch. I’m more or less the closest thing to a biologist in our office, so I took a look. I had no idea what it was, but I was pretty sure I could find out, and I used my phone to take a couple terrible photos.

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Then, I turned to the number one tool of a naturalist in need of ID help: Twitter.

Yup, I took shameless advantage of my entomology contacts on Twitter – again – and in less than forty-five minutes I had an answer. This is a nest built by the caterpillars of a pine-munching moth, and that stuff it’s made of is frass, or caterpillar poop. The next day I ran into the woman who’d brought it in and told her, and she was very interested, if a little repulsed.

Social media: it’s not just for posting photos of what you had for lunch. It’s also for posting photos of balls of caterpillar poop.